Manufacturing for virtual and augmented reality systems and components
Disclosed is an improved diffraction structure for 3D display systems. The improved diffraction structure includes an intermediate layer that resides between a waveguide substrate and a top grating surface. The top grating surface comprises a first material that corresponds to a first refractive index value, the underlayer comprises a second material that corresponds to a second refractive index value, and the substrate comprises a third material that corresponds to a third refractive index value. According to additional embodiments, improved approaches are provided to implement deposition of imprint materials onto a substrate, which allow for very precise distribution and deposition of different imprint patterns onto any number of substrate surfaces.
1. A method for manufacturing a diffractive optical element, comprising:
depositing a first material on a first face of a substrate;
employing a first template having a first imprint pattern formed thereon to form a first pattern into the first material on the first face of the substrate;
depositing a second material on a second face of the substrate; and
employing a second template having a second imprint pattern formed thereon to form a second pattern into the second material on the second face of the substrate.
2. The method of claim 1 , wherein the first pattern includes an incoupling grating and a first diffractive optical element.
3. The method of claim 2 , wherein the second pattern includes an unmodified portion aligned with the incoupling grating across the substrate.
4. The method of claim 2 , wherein the second pattern includes a second diffractive optical element aligned with the first diffractive optical element.
5. The method of claim 1 , wherein the first material is deposited with a substantially uniform depth.
6. The method of claim 1 , wherein the first imprint pattern on the first template has a first portion having a first height and a second portion having a second height, such that the first pattern formed into the first material has an incoupling grating having a first depth and a first diffractive optical element having a second depth.
7. The method of claim 1 , further comprising flipping the substrate between employing the first template to form the first pattern and employing the second template to form the second pattern.
8. The method of claim 1 , wherein forming the first pattern and the second pattern on respective first face and second face of the substrate implements multiplexing of functions through the substrate such that different eyepiece functions are implemented without adversely affecting grating structure function.
9. The method of claim 8 , wherein the multiplexing of functions through the substrate comprises:
applying light to the substrate through an in-coupling grating;
a first portion of the light exiting the first face of the substrate to implement a first function; and
a second portion of the light exiting the second face of the substrate to implement a second function.
10. The method of claim 1 , wherein the first and second materials comprise the same type of material.
11. The method of claim 1 , wherein the first and second materials comprise the different types of material.
12. The method of claim 1 , wherein the first imprint pattern of the first template is the same as the second imprint pattern of the second template.
13. The method of claim 1 , wherein the first imprint pattern of the first template is different from the second imprint pattern of the second template.